Phosphorus oxychloride → 7-chloro-2-heptylthio-6-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one

Participants

Reaction Steps

A mixture of 19.5 g of the thus obtained 2-heptylthio-7-hydroxy-6-methyl-5H-1,3,4-thiadiazolo-[3,2-a]pyrimidin-5-one, 38 g of phosphorus oxychloride and 13.6 g of phosphorus pentachloride was warmed to 77°~88° C. and was stirred for 2 hours. The reaction solution was concentrated under reduced pressure, thereafter the residue was dissolved in toluene, and the solution was washed with a potassium carbonate aqueous solution and water respectively. After the solution was dried over anhydrous sodium sulfate, the solvent was distilled off and the residue was purified by column chromatography on a silica gel with an ethyl acetate/n-hexane (2:3) mixture as an eluent. After the solvent was distilled off, 19.0 g of 7-chloro-2-heptylthio-6-methyl-5H-1,3,4-thiadiazolo-[3,2-a]pyrimidin-5-one was obtained.

Provenance & Evidence